Review on Diamond Magic Combo Pack: Powerful 20oz Cleaner & 4-pc. Drill Brush Set - Removes Tough Water Stains & Spots from Shower Doors, Windshields, Windows, Chrome, Tile, Tubs, Stainless Steel by Jeff Rhodes

This glass cleaner is incredible. I had a severely water-stained exterior window that couldn't clear anything. Calcium in the water has accumulated over 16 years. I really thought I had to put a new window in. In a last ditch effort, I bought this product thinking it would be another setback compared to all the others I've bought and tried. Keep it low and this stuff lives up to its reputation. Using a 10 foot glass cleaning cloth, I applied it by hand and in a circular motion watched the window begin to clean. It took 3 attempts but each time the calcium started to disappear. No brushes required, like I said try and you will wash away the white calcium and rust if you have any.